#include<stdio.h>

int main(){
    int hour1,minute1;
    int hour2,minute2;

    scanf("%d%d",&hour1,&minute1);
    scanf("%d%d",&hour2,&minute2);
    
    int t1=hour1*60+minute1;
    int t2=hour2*60+minute2;

    int t=t1-t2;
    printf("liuhancong");
    printf("时间相减等于%d小时%d分钟\n",t/60,t%60);
}